This Bulletin contains the papers presented at a meeting of the International Union of Forest Research Organisations (IUFRO) Project Group P4.02 ‘Economics and Harvesting of Thinnings’, held in Edinburgh from 30 September until 2 October 1974. Papers were invited on various aspects of thinning. The first session (Papers 1-7) mainly concerned the yield aspects of thinning. The second session (Papers 8-10) was devoted principally to the damage caused to sites and stands by harvesting operations. The third session (Papers 11-15), covered, in the main, the harvesting operation. The papers are given more or less in the order in which they were presented, and a much shortened edited version of the discussion attending each paper is given immediately following the paper.